:root {
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-tertiary: #334155;
    --text-primary: #f1f5f9;
    --text-secondary: #cbd5e1;
    --text-muted: #94a3b8;
    --accent: #3b82f6;
    --accent-hover: #2563eb;
    --success: #10b981;
    --error: #ef4444;
    --border: #475569;
    --code-bg: #1e293b;
    --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-mono: 'Courier New', Consolas, Monaco, monospace;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: var(--font-sans);
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    width: 100%;
}

/* Navbar */
.navbar {
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 20px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
    color: var(--text-primary);
    font-weight: 700;
    font-size: 1.25rem;
}

.logo-text {
    font-size: 1.5rem;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 2rem;
}

.nav-link {
    color: var(--text-secondary);
    text-decoration: none;
    transition: color 0.2s;
    font-weight: 500;
}

.nav-link:hover,
.nav-link.active {
    color: var(--accent);
}

.lang-toggle {
    display: flex;
    gap: 0.5rem;
}

.lang-btn {
    background: var(--bg-tertiary);
    color: var(--text-secondary);
    border: 1px solid var(--border);
    padding: 0.4rem 0.8rem;
    border-radius: 4px;
    cursor: pointer;
    font-weight: 600;
    transition: all 0.2s;
}

.lang-btn:hover {
    background: var(--accent);
    color: white;
    border-color: var(--accent);
}

.lang-btn.active {
    background: var(--accent);
    color: white;
    border-color: var(--accent);
}

/* Hero */
.hero {
    text-align: center;
    padding: 4rem 0 2rem;
}

.hero h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.hero-description {
    font-size: 1.125rem;
    color: var(--text-secondary);
    max-width: 700px;
    margin: 0 auto;
}

/* Search */
.search-section {
    padding: 2rem 0;
}

.search-input {
    width: 100%;
    padding: 0.875rem 1rem;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 8px;
    color: var(--text-primary);
    font-size: 1rem;
    margin-bottom: 1.5rem;
}

.search-input:focus {
    outline: none;
    border-color: var(--accent);
}

.topic-chips {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
}

.chip {
    background: var(--bg-secondary);
    color: var(--text-secondary);
    border: 1px solid var(--border);
    padding: 0.5rem 1rem;
    border-radius: 20px;
    cursor: pointer;
    transition: all 0.2s;
    font-size: 0.875rem;
    font-weight: 500;
}

.chip:hover {
    background: var(--bg-tertiary);
}

.chip.active {
    background: var(--accent);
    color: white;
    border-color: var(--accent);
}

/* Examples Grid */
.examples-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.5rem;
    padding: 2rem 0 4rem;
}

.example-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 1.5rem;
    transition: transform 0.2s, border-color 0.2s;
    cursor: pointer;
    text-decoration: none;
    display: block;
}

.example-card:hover {
    transform: translateY(-2px);
    border-color: var(--accent);
}

.example-card-topic {
    color: var(--accent);
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 0.5rem;
}

.example-card-title {
    color: var(--text-primary);
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.example-card-difficulty {
    color: var(--text-muted);
    font-size: 0.875rem;
}

/* Example Page Styles */
.example-header {
    padding: 2rem 0 1rem;
}

.example-title {
    font-size: 2rem;
    margin-bottom: 0.5rem;
}

.example-meta {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
    margin-bottom: 1.5rem;
}

.difficulty-badge {
    background: var(--bg-tertiary);
    color: var(--text-secondary);
    padding: 0.25rem 0.75rem;
    border-radius: 12px;
    font-size: 0.875rem;
}

.difficulty-easy { background: #10b98144; color: var(--success); }
.difficulty-medium { background: #f59e0b44; color: #f59e0b; }
.difficulty-hard { background: #ef444444; color: var(--error); }

.example-content {
    display: grid;
    gap: 2rem;
    padding-bottom: 4rem;
}

.content-section {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 1.5rem;
}

.section-title {
    font-size: 1.25rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.content-section ul {
    margin-left: 1.5rem;
}

.content-section li {
    margin-bottom: 0.5rem;
    color: var(--text-secondary);
}

/* Code Editor */
.code-container {
    position: relative;
}

.code-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.75rem 1rem;
    background: var(--bg-tertiary);
    border: 1px solid var(--border);
    border-bottom: none;
    border-radius: 8px 8px 0 0;
}

.code-label {
    font-size: 0.875rem;
    color: var(--text-muted);
    font-weight: 600;
}

.copy-btn {
    background: var(--accent);
    color: white;
    border: none;
    padding: 0.4rem 0.875rem;
    border-radius: 4px;
    cursor: pointer;
    font-size: 0.875rem;
    font-weight: 500;
    transition: background 0.2s;
    position: relative;
}

.copy-btn:hover {
    background: var(--accent-hover);
}

.copy-btn.copied::after {
    content: 'Copied!';
    position: absolute;
    top: -30px;
    right: 0;
    background: var(--success);
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    font-size: 0.75rem;
    white-space: nowrap;
}

.code-editor {
    width: 100%;
    min-height: 300px;
    padding: 1rem;
    background: var(--code-bg);
    border: 1px solid var(--border);
    border-radius: 0 0 8px 8px;
    color: var(--text-primary);
    font-family: var(--font-mono);
    font-size: 0.9rem;
    line-height: 1.6;
    resize: vertical;
    tab-size: 4;
}

.code-editor:focus {
    outline: none;
    border-color: var(--accent);
}

/* Controls */
.controls {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.btn {
    background: var(--accent);
    color: white;
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: 6px;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 600;
    transition: background 0.2s;
}

.btn:hover:not(:disabled) {
    background: var(--accent-hover);
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.btn-secondary {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

.btn-secondary:hover:not(:disabled) {
    background: var(--border);
}

/* Input/Output */
.input-field {
    width: 100%;
    min-height: 80px;
    padding: 0.75rem;
    background: var(--code-bg);
    border: 1px solid var(--border);
    border-radius: 6px;
    color: var(--text-primary);
    font-family: var(--font-mono);
    font-size: 0.9rem;
    resize: vertical;
}

.input-field:focus {
    outline: none;
    border-color: var(--accent);
}

.output-panel {
    min-height: 120px;
    padding: 1rem;
    background: var(--code-bg);
    border: 1px solid var(--border);
    border-radius: 6px;
    font-family: var(--font-mono);
    font-size: 0.9rem;
    white-space: pre-wrap;
    word-break: break-word;
    color: var(--text-secondary);
}

.output-error {
    color: var(--error);
}

.output-success {
    color: var(--success);
}

/* Related Examples */
.related-links {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.related-link {
    color: var(--accent);
    text-decoration: none;
    transition: color 0.2s;
}

.related-link:hover {
    color: var(--accent-hover);
    text-decoration: underline;
}

/* Footer */
.footer {
    background: var(--bg-secondary);
    border-top: 1px solid var(--border);
    padding: 2rem 0;
    margin-top: auto;
    text-align: center;
    color: var(--text-muted);
    font-size: 0.875rem;
}

/* RTL Support */
[dir="rtl"] {
    direction: rtl;
}

[dir="rtl"] .nav-links {
    flex-direction: row-reverse;
}

[dir="rtl"] .example-meta,
[dir="rtl"] .controls,
[dir="rtl"] .topic-chips {
    flex-direction: row-reverse;
}

[dir="rtl"] .content-section ul {
    margin-right: 1.5rem;
    margin-left: 0;
}

[dir="rtl"] .code-header {
    flex-direction: row-reverse;
}

/* Responsive */
@media (max-width: 768px) {
    .hero h1 {
        font-size: 2rem;
    }
    
    .nav-links {
        flex-wrap: wrap;
        gap: 1rem;
    }
    
    .examples-grid {
        grid-template-columns: 1fr;
    }
    
    .example-title {
        font-size: 1.5rem;
    }
}

/* Accessibility */
.btn:focus,
.chip:focus,
.lang-btn:focus,
.search-input:focus,
.code-editor:focus,
.input-field:focus {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
}

.nav-link:focus {
    outline: 2px solid var(--accent);
    outline-offset: 4px;
    border-radius: 2px;
}